Titanium dioxide is an important material used in many industrial and scientific applications. For example, titanium oxides are an important class of lithium-ion battery electrodes owing to their good capacity and stability within the cell environment. In addition to several naturally occurring polytypes (e.g., brookite, anatase, and rutile), several man-made polymorphs reportedly have been synthesized via ion-exchange, notably TiO2(B) from K2Ti4O9 and TiO2(H) from K2Ti8O16 [1-13]. The particular polytype isolated from a given synthetic process is dependant on variables that include, e.g., the precursor material or materials used to prepare the titanium oxide, the temperature at which the titanium oxide material is produced, and the atmosphere utilized during the production process. Low temperature preparations (e.g., <100° C.) typically yield brookite. Titanium oxide materials prepared above 700° C. generally yield rutile. Anatase generally is isolated from processes run at temperatures between 100 and 700° C. For titanium dioxide materials prepared or annealed under an ammonia atmosphere, nitrogen-doped yellow anatase or rutile has been isolated and characterized [14, 15]. As bulk materials, rutile is electrochemically inactive, brookite inserts about 0.16 Li per formula unit, while anatase, TiO2(H) and TiO2(B) insert about 0.5 Li per formula unit [1,2,7,10]. These differences reflect the different arrangements of the titanium centered octahedra within the crystal structures of the materials and the resultant internal void spaces that are present in the crystal structure. Significant differences and levels of activity have been reported when nanoscale versions of the titanium dioxide materials are evaluated, reflecting the smaller diffusion distances and increasing important role of surfaces [16, 17, 18].
Although most Ti(IV) oxides are poor electronic conductors, new methods developed to synthesize small particle size (e.g., nanometer scale) primary particles have achieved the higher rate capability needed for modern commercial applications. Consequently, there is an ongoing need to develop new methods for synthesizing the various forms of titanium oxides. This need is addressed by the present invention.